Navigational map projection device



June 7, 1949.

R. 1.. DUNCAN NAVIGATIONAL MAI PROJECTION DEVICE Filed May 28,, 1946 ZZZ/44 3mm RICHARD 1.. DUNCAN Patented June 7, 1949 UNITED STATES PATENT OFFICE 2,472,098 NAVIGA ION M ROJ CTION DE IC Richard L. Duncan, West Laiayette, Ind. A plication May 28, 1946, Serial No. 572,901

2 Claims.

(Granted. un er the act of. March 3, .1883, as

amended April 30, 1928; 370 0. G. 757) The present. inven ion relates to a naviga ona device that is compact and one that may be folded int a carry ng ki An object of the present invention is the provision oi a navigational device in which the pilot is able to navigate a sh p without aiarse map in the cockpit.

Another obje t of the present invention is the pr vision of a devic th t w ll indicate at all time the direct reading position without tracing on a map- A st ll iurther ob ect of the p esent in ntio is the provision of; a micro-film men o a comnosi e air ays chart ho ing he complete Un ted S ates. 7

A s i l further object of the present invention is the provision of means fo p ojecting t e map on a screen.

.A ill fu ther ob ect of t e P s nt nventi n is the provision oi m ans f r locati g a len over any desired position, and means for causing the lens to travel in a direction desired, and at a speed proportional to. the ground speed desired,

A still iurther object oi the. present invention is the provision of means tor electrically controlling the lens.

Other objects and advantages of the invention will be me pparen durin the course of the folw n tail d escr ption, wh n taken in connection with the accompanying drawings, in which:

Fig. 1 is a diagrammatic perspective view of the device with portions broken away;

Fig. 2 is a schematic view of the switch device;

Fig. 3 is a side elevational view of the latitude drive mechanism and geared setting dial Fig. 4 is a plan view or the wiring diagram for the switch shown in Fig. 2, and means for 60htrolling the drive screws; and

Fig. 5 is a fragmentary view of the switch contact portion.

In the drawings, the numeral represents a nav ational device in the form of a collapsible cabinet wh ch comprises a base ii, the base H housing lens control elements that comprise a screw drive 12 calibrated in latitude, and a screw drive l3 disposed at right angles to the screw I2 and calibrated in longitude. The latitude shaft has one end portion l4 passing through a block IS, the opposite end being housed in block (6 which is threaded and receives the longitudinal screw drive [3. The latitude drive is driven by a gear H which is secured to the end portion H of shaft l2, and this gear meshes with a slidable worm gear I8 on a spline shaft 19. One end of the spline shaft I9 is connected to motor 20. shown in Fig. 4. The oppo ite. end of sh lt s mo vided with a gear 2| which meshes with a gear 32 that is secured to one end of. shaft 23. the oppo ite end of shaft 23. having a calibrated d al :4. Qn and or the longitudinal screw drive I3 is con-- n c ed to motor 25, the opposite end bein pro.- vided with a dial 2.5.-

The sid s 2 and 2.8 of the cabinet are ri id and a hingedly mounted to th base H by hin es 25. the upper inner face of the si es 21. and 28 i g p i w th. r o 30 which receives a lass view n scree 3!. The front and h els of the. cabinet. at th hin e line to the top. are closed in by cloth material 3.2 which may be detachahlr secured o the side members. 2: n 28 by any su able means w l known in the art. such as snep on ho k Within the cabinet 10 the e is provided a bol lows .33, the upper end 34 being secured to the sides 21 nd, 23. adjacent the t p edge lay-any suitable means. The bellows 3.3 tapers downwardly. the lower end 35 being s cured by any suitable means to a plate 36, the plate having a block .31 that is integral with the plate 36, the block being provided with a threaded bore that receives the screw drive 12. The plate 36 is provided with an aperture that receives a portion of a lens housin 35- To th p ate 3.6 is secured a bracket at that suppor s an electric light 40, the li ht having wires II that connect with a source of cur-rent. Below the ligh and the lens and housed in the base of the cabinet, is a micro-film map 42 of composite ai w y charts showin the entir United States.

In Fig. 2 I have shown a schematic view of my novel switch device that comprises a frame 50 within whi h th e is mounted resistance elements 1 for controlling the clockwise movement oi m er 29. and res stance element 52 for comti lImg the counterclockwise movement of mo te 0- eeistanee element 53. controls the clockwise movement of motor 25. and resistance ole-.- 54 controls the counterclockwise movement of motor 25. The frame 50 is provided with a bar 55 having conducting strips 63 and 64, the strip 63 being in sliding contact with resistance elements 53 and 54 that are mounted on the supporting bar 60, the upper strip 64 being in sliding contact with resistances 5| and 52 which are mounted on a supporting bar 6|, each bar having a longitudinal slot 58 and 59 respectively, the arm 55 also having a longitudinal slot 16 which always intersects at a common point by means of the common pin 51 passing through all of the slots. As the pin is moved by its handle 62 to any point of the slot 16 in the arm 55 in accordance with the flight speed of the aircraft; and the arm 55 turned in any direction about the center 56 in accordance with the direction of flight path, the strips 63 and 64 make contact with the corresponding resistances at the proper point to control the motors 20 and 25 by means of circuit connections shown in Fig. 4 to drive screws I 2 and I3 at proper speeds to reproduce the path of the aircraft by moving the lens over the corresponding path on the micro-film map, thus producing an image on the screen 3| which continually moves and presents the actual image of the actual terrain flown over by the aircraft when once set properly at any given starting point. The switch device may be remotely located and connected to the cabinet I 0 by electric cable shown as power leads 65, 61, 69 and in Fig. 4.

In Fig. 4 in the schematic wirin diagram, each motor and has power leads for forward and reverse operation 61, 65, I0 and 69 respectively and a common ground 72 and 14. The forward power line 6'! is connected to and through the resistance 5! to contact strip 63 which is connected to the power source 66. The power line 65 is connected in the same Way through resistance 52, the power lines 69 and T0 are connected in like manner through resistances 53 and 54 respectively to the contact strip 64 which is also connected to the power source 66.

In the operation of the device, the lens 38 is positioned over the point on the micro-film map representing the local position of the aircraft by moving the calibrated dials, then the switch is positioned by handle 62 in accordance with the flight path that is in accordance with direction and speed of flight, whereupon the motor 20 and 25 will continuously move the lens so as to move the image on the screen 3| at the same rate in the opposite direction reproducing the motion of the actual terrain over which the aircraft is travelling so that the flight path may be checked with the map.

It is to be understood that while the embodiment of the invention which has been described is to be preferred, changes may be made in the construction and arrangement of parts without departing from the spirit and scope of the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. A navigational device comprising a housing, a translucent screen secured at one end of said housing, a micro-film positioned parallel to said screen near the other end of said housing, a screw shaft journaled in said housing along one side thereof, a variable speed reversible motor adapted to rotate said screw shaft, a splined shaft 4 driven by a similar motor and journaled in said housing at the other side thereof parallel to said screw shaft, a worm gear slidable on said splined shaft and rotatable therewith, a second screw shaft journaled at one end on an internally threaded block threadably engaged with the firstnamed screw shaft and drivably connected by gear at the other end to said worm gear, a second internally threaded block movable on said second screw shaft, two adjustable dials calibrated one each in longitude and in latitude secured one each to the end of said first named screw shaft and to said splined shaft, a l ns s tem mounted on said second internally threaded block and movably positioned between said micro-film and said screen, a light source secured to said lens system and movable therewith, and remote switch means for controlling the speed and direction of rotation of said motors whereby said lens system moves between said micro-film and said screen projecting filmed data thereon. 2. The device as set forth in claim 1 in which the switch means comprises two resistance bars connected one to each of the two motors and mounted at right angles to each other, said bars adapted to slide across a square space in adjacent planes, each of said bars being composed of a forward and reverse operating control rheostat coil, said rheostats having their zero speed ends at the middle of each bar and providing for similar gradual increases in speed toward their outer ends, a contact bar swiveled at the center of said square space and having strips on opposite sides for sliding contact with said rheostat coils, axial slots one each in said contact bar and each of said rheostat bars, a pin for simultaneous sliding operation in said three slots, a handle secured to said pin for moving said pin over any point in said square space, said point determining the speed and direction of movement of said lens system across said micro-film in accordance with the distance and direction of said pin from the center of said square space, whereby an image of said course terrain is progressively projected from said micro-film on said screen.

RICHARD L. DUNCAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 994,276 Reilly June 6, 1911 ,199,942 Taylor Oct. 3, 1916 1,889,575 Sebille Nov. 29, 1932 2,186,330 Fitzgerald Jan. 9, 1940 2,267,649 Graves Dec. 23, 1941 2,314,497 Hargrave et a1. Mar. 23, 1943 FOREIGN PATENTS Number Country Date 362,949 Germany Nov. 3, 1922 615,660 Germany July 10, 1935 

